The invention is generally directed to a closure system and a container having a closure system.
Tubes, bottles or similar containers of fluid or liquid or paste-like media include outlet openings which are closable by means of closures such as, for example, screw-on lids or snap-on protective caps.
EP1188679A2 discloses an automatic closure for resiliently deformable, tube-like or bottle-like containers of paste-like or liquid media. The closure includes a cover lid with an outlet opening and an axially movable closing member for closing said outlet opening. The closing member is realized as part of a cover-like resilient hollow body. The medium passes from the container into a space between the outside surface of the hollow body and the cover lid. As a result of pressure from the outside onto the container, the medium is pressed into the space and there exerts a compressive force onto the outside surface of the cover-like hollow body. This causes the closing member to be moved axially away from the outlet opening in opposition to the restoring force of the hollow body. Due to the overpressure in the space, the medium is pressed out of the space through the outlet opening. As the restoring forces of such membrane-like hollow bodies are often insufficient to move the closing member back again into the closed position, EP1188679A2 proposes realizing ventilation ducts to the interior of the hollow body and to the space between the outside surface of the hollow body and the cover lid. In particular in the case of media with comparatively high viscosity, the restoring force of membrane-like hollow bodies can be too small, even in combination with ventilation ducts, to displace the viscous medium and to close the valve in a reliable manner. Increasing the restoring forces, for example, as a result of greater wall thicknesses and/or as a result of choosing a different material combination, can result in unacceptably high actuating forces in particular in the case of highly viscous fillers.
In particular in the case of preservative-free media or fillers, it is important that contaminated filler is not able to flow back into the respective container after an application. This also applies analogously to air contaminated with germs and/or dirt particles. As germs are also able to pass into a container from the outside via a filler film, it is important to seal the outlet opening well in particular when it is not in use.